Hi. About the magenta color that disappears, there is transparency involved in that area? If so, maybe is a flattening problem in the export process. Which PDF preset are you using for exporting?
Nope, i didn't put any trasparency. For the PDF, I exported flagging "optimize for fast web view" but it doesn't work and the preview it's wrong. Also for .ai preview in my mac it's like this.
Are using the same color management settings?
Hi Monica, what do you mean? I tried to export .ai and .pdf in CMYK and in RGB but always same problem as well.
Adobe doesn't really have in-depth information about how color management works, but there is an introduction: https://helpx.adobe.com/acrobat/using/color-management.html
You need to understand it. It's built into the very base of every (!) publishing application. Just clicking every button trial and error won't help.
Do the color values changes as well?